Binding-post and jack-plug unit for electrical installations



H. P. BLAKE Aug. 19, 1941.

Filed Sept.. 14, 1940 Patented Aug. 19, 1941 BINDING-POST AND JACK-PLUG UNIT FOR ELECTRICAL INSTALLATIONS Herbert P. Blake, Springfield,` Mass., assigner to The Standard Electric Time Company,

iield, Mass., a corporation of Connecticut Spring- Application September 14, 1940, Serial No. 356,820

2 Claims.

The present invention relates to improvements apparatus are tested and wherein 'a service-panel is provided from which electric current of various chaarcteristics may be tapped off for use in the test. The characteristics `of the current supply made available by the service-panel usually vary with regard to voltages, frequency, etc., etc.

One of the objects of the present invention is to provide a superior and low cost electrical laboratory accessory which will facilitate the connection of various piecesof electrical apparatus to sources of current supply of various characteristics.

A further object of the present invention is to provide a superior unitary device which is adapted to act both as a binding-'post and as a jackplug to thus permit the ready and convenient connection of various pieces of electrical apparatus directly to a service-panel without requiring the intervention ofintermediate wiring. With the above and other objects in View, as will appear to those skilled in the art from the present disclosure, featuresl in thel said disclosure which are novel over the prior art and which are not claimed in any separate application.

In the accompanying drawing, in which certain modesof carrying out shown for illustrative purposes:

Fig. 1 is a view mainly in central-longitudinal section and partly in side elevation and showing vthe improved binding-post and jack-plug unit of the present invention, portion of a service-panel and a female jackmember, which latter is shown in central-longitudinal section;

Fig. 2 is a transverse sectional View taken on the line 2--2 of Fig. 1;

Fig. 3 is a view in central-longitudinal section of the improved binding-post and jack-plug unit 'detached from the female jack-member and shown in readiness to clamp an inserted wire;

Fig. 4 is a transverse sectional view taken on 'f the line 4--4 of Fig. 3; and

Fig. 5 is a view in side elevation of the body of the jack-plug, detached.

The particular binding-post and jack-plug herein chosen for the illustration of the present this invention includes all the present inventionare together with a (cina-363) invention comprises a rod-like body III preferably formed of spring brass or other suitable electroconductive material. About midway of its length the body I0 is provided with a rigid annular collar I I which may be formed integral with the said body I0, if desired, and which serves, in effect, to divide the said body into an inner jack-plug portion I2 and an outer binding-post portion I3.

'The binding-post portion I3 of the body III is formed at its outer end, in the particular construction shown, with an externally-threaded head I4 larger in diameter than the adjacent part of the said portion I3 so as to provide a stop-shoulder I5 facing toward the collar I I, as is clearly shown in the drawing. The said externally-thread'ed head I4 is threaded into the internally-threaded interior of a cup-shaped binding-nut I6 formed of brassor other suitable electro-conductive material and adapted to be threaded toward and away from the outer face of the collar II of the body I0.

Substantially all of the surface of the binding-nut I6 above referred to save its inner face, is covered by an insulating-cap I1 formed of rubber or other suitable insulating material and preferably molded directly onto the said bindingnut so as to be rigidly coupled to the surface thereof. Adjacent its inner end, a peripheral portion of the binding-nut I5 is forced inwardly to provide a stop-lug I8 which is engageable with the stop-shoulder I5 to limit the outward movement of the said binding-nut relative to the body I0. The indenting of the binding-nut IB to provide the stop-lug I8 is effected after the said binding-nut has been threaded onto the head I4 and preferably prior to the application of the insulating-cap I1.

Immediately forwardly of the rigid collar II, the binding-post portion I3 of the rod-like body Iil is provided with a diametrically-extending wire-receiving passage I9 for the reception of the bared terminal-end 20 of an electric Wire 2I leading from 'a piece of apparatus to be tested or operated.

Preferably, the periphery of the collar II of the body I0 is knurled or milled and the major portion thereof, "as well as the inner 'face of the said collar and a portion of the jack-plug portion I2, is enveloped by a cup-shaped insulatingpad 22 formed of rubber or other suitable insulating material and which is preferably molded in place so as to form `a rigid part of the rodlike body I0.

The jack-plug portion I2 of the rod-like body I is formed with a slot 23 extending longitudinally and diametrically thereof to enable opposed complemental portions to yield laterally. The jack-plug portion I2 is adapted to fit snugly within a forwardly-opening socket 24 formed in the bifurcated forward portion of a female jackmember 25 composed of spring brass or other suitable electro-conductive material. The said female jack-member 25 is housed mainly within a cup-shaped casing 26 formed of insulating material and having in its bottom wall a central passage 2'I through which rearwardly extends an externally-threaded stem 28 formed integral with the jack-member 25. Immediately to the rear of the bottom wall of the casing 26 and bearing thereagainst is a retaining-nut 29 threaded onto the stem 28. Also threaded onto the stem 28 is a clamping-nut 30 serving to clamp the bared terminal-end 3I of a power-supply wire 32 between two complemental The open forward end of the cup-shaped casing 26 rests against the rear face of a service-panel 34 which may be formed of Bakelite or the like or, if desired, of metal.

The service-panel 34 is provided with a transverse aperture 35 with which the open forward end of the casing 26 is aligned and through which extends the cuif-like ange 36 of a retaining-cap 3'! formed of suitable insulating material. is externally threaded for engagement with the internally-threaded forward interior portion of the cup-shaped casing 26, as is shown in Fig. 1. The said retaining-cap 31 is also formed with an annular outwardly-extending flange 38 having its rear face seated against the front face of the service-panel 34 around the aperture 35 therein. The retaining-cap 31 is also formed in its forward portion with an inwardly-extending guard-flange 39 having a central aperture 4E] therein through which the jack-plug portion I2 of the body I is insertable and removable.

In use,v the binding-post and jack-plug unit shown as separate in Fig. 3 has the electric wire 2l leading from the apparatus or instrument to be tested installed, in the wire-receiving passage I 9 while the said unit is entirely removed from the female jack-member in the service-panel 34. After the binding-nut I5 has been clamped against the terminal 20 of the wire EI, lthe jack-plug member may have its jackplug portion I 2 inserted through the aperture 40 in the retaining-Cap 3l and into friotional and hence electrical engagement with the female jack-member 25, as shown especially well in Fig. l. It will be noted that the bared terminal-end 20 of the wire 2l leading from the instrument or apparatus to be tested is well shielded against extraneous contact, by the insulating-Cap I'I and the insulating-pad 22 when the binding-nut IS is threaded down into clamping engagement with the said terminal-end 26. The collar I! of the rod-like body I of the jackplug unit serves by means of its insulating-pad 22 to limit the penetration of the jack-plug portion I 2 into the interior of the female jack-member 25.

When it is desired to use the binding-post and jack-plug unit best shown in Fig. 3, to connect a lead of an instrument or Iapparatus to be tested or operated, the said jack-plug unit is first detached or separated from the female jack-member, after which the binding-nut I 6 may be unthreaded to release the terminal-end metallic washers 33-33.

The said flange 36 of the retaining-cap 3l 20 of the wire 2| preparatory to inserting the lead-wire of another instrument or piece of apparatus into the wire-receiving aperture I 9 for ultimate clamping in place therein by means of the binding-nut I6.

By providing a combined binding-post and jack-plug unit of the character shown, the laboratory worker may connect the lead wire of a piece of apparatus directly to the service-panel without exposing himself or co-workers to the hazards of exposed terminals.

The invention may be carried out in other specific Ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

I claim:

1. A jack-plug unit comprising: a body formed of electro-conductive material and including a threaded binding-post portion at one end, a jack-plug portion at its opposite end and a laterally-extending electro-conductive collar-located intermediate the two said portions and of larger dia-meter than both thereof, the said collar being positioned on the said body to provide an abutment to limit the penetration of the said jackplug portion into a female jack-member; a binding-nut threaded to the threaded binding-post portion of the said body and threadedly movable thereon to clamp a wire in electrical engagement therewith; a cup-shaped insulatingcap rigid with and extending over substantially all save the inner portion of the said bindingnut which faces toward the collar of the said body; and a cup-shaped insulating-pad having its open end facing toward the open end of the cup-shaped insulating-cap and extending around the periphery of the collar of the said body and over 'the face thereof which is directed toward the said jack-plug portion thereof.

2. A jack-plug unit comprising: a body of electro-conductive material and provided intermediate its respective opposite ends with a transverse wire-receiving passage, the said body including a threaded binding-post portion at one end. a jack-plug portion at its opposite end and a laterally-extending collar located intermediate the two said portions adjacent the said transverse wire-receiving portion and of larger diameter than both thereof. the said collar being positioned on the said body to provide an abutment to limit the penetration of the said jackplug portion into a female jack-member; a binding-nut threaded to the threaded binding-post portion of the said body and threadedly movable thereon toward the said collar and toward the transverse wire-receiving passage in the said body to clamp a wire in electrical engagement with the latter; a cup-shaped insulating-cap rigid with and extending over substantially all save the inner portion of the said binding-nut which faces toward the collar of the said body; and a cup-shaped insulating-pad having its open end facing toward that open end of the said cup-shaped insulating-cap and extending around the periphery of the collar of the said body and over the face thereof which is directed toward the said jack-plug portion of the said body.

HERBERT P. BLAKE. 

